"I definitely condemn what happened," said Frank Ancona, imperial wizard of the Traditionalist American Knights of the KKK, in an interview with USA TODAY Network. "It was an act of hate."

Frazier Glenn Cross, 73, a longtime white supremacist linked to the KKK in the 1980s, was charged with premeditated murder for the deaths of a 14-year-old boy and the boy's grandfather, who were both Christian, and a female victim, whose identity has not been released.

The organization today is among the weakest sectors of the white supremacist groups, said Mark Potok, a senior fellow with the Southern Poverty Law Center, which tracks hate groups.There is more "energetic activism" among other groups, such as skinheads and neo-Nazis, he said. KKK members number about 5,000-8,000 nationwide, according to the law center.

Ancona defines the KKK as a Christian white group.

"We've had a few members who have become bad apples, and the whole organization is overall cast in the same light," Ancona said.

Today, the KKK does background checks on new members in an effort to screen applicants for violent crimes and drug abuse, he said.

"The Klan tends to be quite inward-turned," Potok said.

What are the origins of the KKK?

The KKK was formed in 1865, during Reconstruction at the end of the Civil War, with an aim to intimidate black people.

Lynchings, rapes and other violent attacks became a staple of the white supremacist movement associated with the Klan, according to the law center. By 1925, the Klan had 4 million members.

During the Civil Rights era of the 1960s, the Klan became one of the biggest opponents to desegregation. The Klan was responsible for a 1963 church bombing in Birmingham, Ala., that killed four girls.

Since the 1970s, the Klan has weakened because of internal conflicts, court cases and government infiltration, according to the law center.

What are the suspect's ties to the KKK?

Cross, who is also known as Frazier Glenn Miller, founded and ran the Carolina Knights of the KKK in the 1980s, according to the law center.

In 1987, Cross was the subject of a nationwide manhunt after violating a court order prohibiting him from operating a paramilitary organization. He served three years in prison for weapons charges and for plotting the assassination of the SPLC founder.

Cross "comes from a different era of the Klan," Potok said. "The Klan was a lot scarier then."

In recent years, Cross wrote anti-Semitic articles and distributed The Aryan Alternative, a racist, hate-filled publication.

"He spoke in incredibly violent ways, but the sad reality is, hundreds if not thousands are rather similar," Potok said.